Dac's Auto-latch has been around for quite awhile. They are a mechanical gate latch that is quite reliable. It was designed to work with a "gravity hinge" set up. Offered in either one way or two way swing applications for chain link gates. Though it will work with most hinge types.
This set up is self closing and self latching it eliminates any need for a spring closer. There is one draw back, and that is the bottom hinge contains a "pinch point" that can cause damage to a childs finger if it happens to be stuck in there at the wrong time. kids do odd things, we all know that.
The system does work well, is pool code compliant, requires practically no maintaince & is reasonably priced. This system when properly installed offers years of reliable self closing, self latching service.
If you are looking for parts or service for these, Bay Area Fence Factory is your source 727.726.7554